For internal combustion engines, such as diesel engines, nitrogen oxide (NOx) compounds may be emitted in the exhaust. To reduce NOx emissions, a selective catalytic reduction (SCR) process may be implemented to convert the NOx compounds into more neutral compounds, such as diatomic nitrogen, water, or carbon dioxide, with the aid of a catalyst and a liquid reductant. The catalyst may be included in a catalyst chamber of an exhaust system, such as that of a vehicle or power generation unit. A liquid reductant, such as anhydrous ammonia, aqueous ammonia, diesel exhaust fluid (DEF), or aqueous urea, is typically introduced into the exhaust gas flow prior to the catalyst chamber.
To introduce the liquid reductant into the exhaust gas flow for the SCR process, an SCR system may dose or otherwise introduce the liquid reductant through a dosing module that vaporizes or sprays the liquid reductant into an exhaust pipe of the exhaust system up-stream of the catalyst chamber. In some applications, such as high horsepower applications, the reductant may form deposits that may collect within the exhaust pipe. These deposits accumulate over time and may correspondingly decrease the efficiency (e.g., conversion efficiency, etc.) and, therefore, the desirability of the SCR process.